If glofitamab were applying for a job, the hiring manager would slide across the table a truly ridiculous posting: must hunt lymphoma inside the brain, slip past the blood-brain barrier, wake up tired T cells, and try not to set off too much immune chaos on the way in. Most applicants would stare at that description, mutter something polite, and leave through the nearest fire exit.
That is why this new real-world study on relapsed or refractory primary CNS lymphoma caught my eye.[1] Primary CNS lymphoma is a nasty, uncommon B-cell lymphoma that sets up shop in the brain, spinal cord, eye, or surrounding fluid, which is rather like choosing the most heavily guarded neighborhood in medicine.[2] The blood-brain barrier exists for good reason - it keeps stray trouble out - but it also makes drug delivery a bureaucratic nightmare. For decades, neuro-oncology has been full of clever ideas that looked marvelous on paper and then bounced off the barricades like underfunded suitors.
The Bouncer at the Door
Glofitamab is a bispecific antibody. One arm grabs CD20 on lymphoma cells, the other grabs CD3 on T cells, essentially dragging the immune system over to the problem and saying, "No, no, this one. Focus." Bispecifics have already become serious players in systemic large B-cell lymphoma, especially after glofitamab entered U.S. practice in June 2023 for selected relapsed or refractory large B-cell lymphomas.[3-5] The unanswered question was whether this trick would work in the central nervous system, where many therapies arrive late, confused, and underdressed.
In this multicenter study, 16 adults with relapsed or refractory primary CNS lymphoma received glofitamab monotherapy.[1] The interim overall response rate was 75%, with complete responses in 50%. Median progression-free survival was 15.4 months, and median overall survival had not yet been reached at reporting. For a disease with few dependable rescue options, those numbers are not small potatoes. They are the sort of results that make clinicians stop stirring their coffee.
Not Just a Good Story - A Measurable One
The most satisfying part is that the investigators did not simply say, "Well, perhaps the drug got in there somehow." They checked. Glofitamab was detectable in cerebrospinal fluid in 60% of tested patients, with CSF-to-plasma ratios up to 0.44%.[1] That may sound tiny, but in CNS oncology, tiny measurable entry can be the difference between theoretical ambition and an actual pharmacology story.
They also followed cerebrospinal fluid circulating tumor DNA, or ctDNA. This is one of those modern ideas that would have sounded like science fiction when some of us were younger and still being told interferon would sort everything out by Christmas. Tumors shed fragments of DNA into nearby fluids, and those fragments can act like molecular breadcrumbs. In this study, early ctDNA clearance tended to track with radiographic response, while persistent or returning ctDNA showed up before obvious clinical progression.[1] That fits neatly with recent reviews suggesting CSF liquid biopsy may help diagnose, monitor, and perhaps one day predict relapse in CNS lymphomas, though it still needs proper standardization before becoming routine.[6,7]
Why This Matters Outside the Conference Hallway
Relapsed primary CNS lymphoma is one of those diseases that keeps reminding doctors to stay humble. Standard frontline therapy often leans on high-dose methotrexate-based regimens, but once the disease comes back, the map gets patchy in a hurry.[2,8] Some patients can proceed to transplant or CAR-T therapy, but many cannot, and even when they can, logistics, toxicity, and timing loom over the whole business.[5] An off-the-shelf immunotherapy that shows real activity in the CNS is therefore attractive for very practical reasons. It could serve as treatment, as a bridge to CAR-T, or as a way to buy time without waiting for a custom cellular product to be manufactured.
That last point matters in the real world, where lymphoma does not politely pause while paperwork, insurance, and cell processing grind along. Tumors, regrettably, have no respect for administrative workflow.
The Fine Print, Which Deserves Respect
This was a small study, and it was not a randomized trial.[1] Several patients later received CAR-T or autologous stem cell transplantation, which muddies any attempt to give glofitamab sole credit for long-term outcomes. Safety also deserves plain speech. Most adverse events were grade 1-2, and two patients had grade 3 or higher neurotoxicity that improved with corticosteroids. But two additional patients died from immune effector cell-associated neurotoxicity syndrome after CAR-T consolidation.[1] That does not erase the signal of benefit, but it does remind us that immune therapy in the CNS is not a parlor game. The brain is not fond of inflammatory improvisation.
Still, the direction of travel is hard to miss. Other recent reports and case-based studies are circling the same conclusion: glofitamab appears capable of crossing into the CNS and producing meaningful responses in selected patients with CNS lymphoma.[9,10] If larger prospective studies confirm this, we may be watching the early chapters of a genuine shift - not a miracle, not a coronation, but a credible new hire for one of oncology’s most difficult jobs.
References
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Yang A, Dong J, Deng X, et al. Multicenter Real-World Analysis of Glofitamab in Relapsed/Refractory Primary CNS Lymphoma: Clinical Activity, CNS Penetration, and ctDNA Dynamics. Am J Hematol. 2025. DOI: https://doi.org/10.1002/ajh.70342 | PubMed: https://pubmed.ncbi.nlm.nih.gov/42035265/
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Grommes C, DeAngelis LM, Ferreri AJM, et al. Primary central nervous system lymphoma. Nat Rev Dis Primers. 2023;9:29. DOI: https://doi.org/10.1038/s41572-023-00439-0 | PubMed: https://pubmed.ncbi.nlm.nih.gov/37322012/
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FDA granted accelerated approval to glofitamab-gxbm on June 15, 2023, for selected relapsed or refractory large B-cell lymphomas. FDA summary: https://www.fda.gov/media/186557/download
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Dickinson M, Carlo-Stella C, Morschhauser F, et al. Glofitamab for Relapsed or Refractory Diffuse Large B-Cell Lymphoma. N Engl J Med. 2022;387:2220-2231. DOI: https://doi.org/10.1056/NEJMoa2206913 | PubMed: https://pubmed.ncbi.nlm.nih.gov/36507690/
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Trabolsi A, Arumov A, Schatz JH. Bispecific antibodies and CAR-T cells: dueling immunotherapies for large B-cell lymphomas. Blood Cancer J. 2024;14:27. DOI: https://doi.org/10.1038/s41408-024-00997-w
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Nayak L, Bettegowda C, Scherer F, et al. Liquid biopsy for improving diagnosis and monitoring of CNS lymphomas: A RANO review. Neuro Oncol. 2024;26(6):993-1011. DOI: https://doi.org/10.1093/neuonc/noae032 | PMCID: https://pmc.ncbi.nlm.nih.gov/articles/PMC11145457/
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Natsumeda M, Shibuma S, Takahashi H, et al. Recent advances in liquid biopsy of central nervous system lymphomas: case presentations and review of the literature. Brain Tumor Pathol. 2024;41(2):85-91. DOI: https://doi.org/10.1007/s10014-024-00483-y | PubMed: https://pubmed.ncbi.nlm.nih.gov/38597999/
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Ferreri AJM, Cwynarski K, Pulczynski E, et al. Primary central nervous system lymphomas: EHA-ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up. Ann Oncol. 2024. DOI: https://doi.org/10.1016/j.annonc.2024.05.002 | PubMed: https://pubmed.ncbi.nlm.nih.gov/38839484/
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Wang W, Chen M, Li J, et al. Glofitamab induces deep and rapid response in relapsed primary central nervous system lymphoma. Leuk Lymphoma. 2025;66(8):1475-1480. DOI: https://doi.org/10.1080/10428194.2025.2484365 | PubMed: https://pubmed.ncbi.nlm.nih.gov/40174220/
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Neumann MA-C, Schneider J, Szameitat M, et al. Glofitamab crosses the blood brain barrier and exhibits activity against primary and secondary CNS lymphoma. Blood Adv. 2026. DOI: https://doi.org/10.1182/bloodadvances.2025019322 | PubMed: https://pubmed.ncbi.nlm.nih.gov/41785308/
Disclaimer: The image accompanying this article is for illustrative purposes only and does not depict actual experimental results, data, or biological mechanisms.